If your wrist sprains constantly without you knowing what could be wrong?

A few things come to mind:

• Tendon and Ligament problems -- too loose to keep the bones in joint
• Deformities -- possibly congenital -- around the wrist (double-jointedness).
• Damage to any of the joint surfaces that fail to keep the bone in place.

I'd want to see imagery to make sure.

I agree with the answer above.

The diagnosis would be easier to make with a description of the symptoms you are having, by imaging (xray first, but may require MRI), and by actual physical exam. Physical exam would be very important, as joint laxity or point tenderness can be a big giveaway.

Some thoughts:

Could you have a stress fracture?

Could this be carpal tunnel syndrome?

Nerve problems can cause pain as well

Arthritis of the wrist or 1st carpo-metacarpal joint can also be quite painful.

Tendinitis in the wrist is very common.

Any prior wrist problems?

As noted, a complete history, physical exam, and prudent imaging as indicated would be very helpful. Also knowing your work history, your age, and your usual activity would be helpful.